Unloading valve



May 5, 1931.

WI TOWNSEND UNLOADING VALVE Filed Oct. 27, 1927 4 Sheets-Sheet l INVENTOR William Townsend,

' ATTORNEYS May 5, 1931.

W. TOWNSEND UNLOADING VALVE Filed Oct. 2'7. 1927 4 Sheets-Sheet 2 INVENTOR Will/am Townsend,

ATTORNEY5 y 5, 1931- w. TOWNSEND 1,804,133

' UNLOADINGVALVE Filed Oct. 27. 1927 4 Sheets-Sheet 3 ATTORN EYS May 5, 1931.

W. TOWNSEND UNLOADING VALVE Filed Oct. 27. 1927 4 Sheets-Shet 4 INVENTO William firms End,

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ATTORN EY$ Patented May 5, 1931 umrw STATES PATENT OFFICE.

WILLIAM TOWNSEN OF CHICAGO, ILLINOIS, ASSIGNOR TO THE QONNERSVIIQLE BLOWER COMPANY, INC., on CONNERSVILLE, INDIANA, A CORPORATION or INDIANA UNLOADING VALVE Application filed October 27,-1927. Serial No. 229,089.

In the use'ofblow'ers of the lobed'impeller type, to provide and maintain a fluid pressure Within a system, delivery from which fluctuates through wide ranges or is, through considerable period's, much less than the capacity of the blower, it is desirable that the resistance toforward movement of the blower be reduced as much as possible.

The objector my present invention is to provide automatic mechanism, dependent upon the fluid pressure in'the delivery system, for automatically controlling delivery of fluid pressure to the delivery system.

The accompanyingdrawings illustrate my invention. I

Fig. l is' aside elevation, in partial vertical section, of an apparatus embodying my invention; Fig; 2is'a fragmentary elevation,

I on an enlarged scale of the mechanism for controlling the positionof' the bypass valve; Fig. 3,.a plan on line 3,- 3'of Fig. 1; Fig. 4:, a' fragmentary plan of the barrel cam andadjacent parts; Fig. 5, an axial section of a modified form'of' bypass valve; Fig.

6, a section of another modified'form of bypass valve; Fig. 7, a view similar to Fig. 1, of'a modified form, andFig. 8 afragmenta ry modification of the construction shown f inFig. 7. I y, p 31) In Figs. 1'to'3 inclusive 10 indicates'the blower which may conveniently be an ordinai'yfb'lowe r of the' interc1igitated rotary lobed impelle'rtype the shaft 11 of one impeller being. projected and provided with a pinion 12, the purpose of which will appear. Blower 10 is provided with an inlet 13 and an outlet l4delivering through a check valve structure 15to the delivery system 16 from which suitable outlets will be provided.

Arranged as a by-pass between outlet 14 and inlet" 13,'around the blower 10, is a system of piping 17 in which is arranged a suitable valve mechanism 18 which will control the flow or possibility of flow through the by-pass piping.

Meshing with pinion 12 is a gear 20 to which is secured a barrel cam C having a cylindrical portion 21, a smaller cylindrical "portion 22, and a connecting portion 23 which connects portions 21. and 22. Riding cam G. is a roller 24- which is rotatably and slidably mounted on a rod 25 carried in the fork 26 of a lever 27 pivoted at 28 on the blower casing. Lever 27 is connected by a link 29 and lever 80 with the stem 31 of valve 18.

Rod 25 is arranged parallel with the axis of cam C and roller 2l is shifted along rod 25, parallel'with the axis of cam C by means of a yoke 35 connected by a link 36 with a lever 37 actuated by the bell'3 8 of amanometer 39 the interior of which is connected by pipe 40 with the delivery system 16. The'operaticn is'as follows: WVhen the apparatus is started and there is no pressure within system 16 bell 38 will be in its lowest position and roller 24 will be riding the small'diameter portion 22, of cam'C beyond portion 23of said cam (the extreme opposite position from that shown in Fig. 2). In this position valve 18 is closed and there is no flow throughthe bypass pipe 17 the entire delivery of the blower p'assing'through the check valve 15 into system 16. As the pressure in system 16 rises roller 24 will be shifted parallel with the axis of cam' C so that intermittently portion 23 of that cam will come beneath saidroller and thus open valve 18 momentarily thereby permitting a portion of the discharge ofthe blower to be by passed around the blower through pipe 17 and thus momentarily relieving the load on the blower.

IVhenever full pressure has beenattained in system 16 and demand therefrom has momentarily ceased, roller 24 will have been shifted to the position shown in Fig. 2

where it is riding continuously upon the I have foundthat it is generally advisable 1cc to rotate cam G somewhat slower than the impellers.

In Fig. 5 I have shown an unbalanced valve 50, of cup form as a substitute for valve 18, said valve being a reciprocatory one. In this form the stem 51 will be connected to lever 30.

In Fig. 6 the cup valve 60 is provided .at one side with a notch 61 and this valve is rotatably and slidably mounted in a cylinder 62 the wall of which is provioed with a notch 63 with which notch 61 may register more or less depending upon the speed of rotation of the valve 60 and its axial position within its cylinder. The stem 64 of valve 60 is splined within a gear 20 meshing with a pinion 12 rotated by the blower. Stem 64 is connected to a yoke 65 carried by a rod 66 which, in turn, will be suitably connected to lever 27, the arrangement being such that the axial position of cup 60 in its cylinder 62, and consequently the degree of registration between notches 61 and 63, will be dependent upon the pressure in the manometer 39.

It will, of course, be readily understood that the piping 17 beyond the valve 18 may lead to atmosphere or some other point instead of leading to the inlet side of the structure and in the claims the term by-pass is used in its broader significance and is not intended to be limited to a structure which returns to the inlet side of the system.

In Fig. 7 a belt 70 leading from shaft 11, operates a crank disc 71 to which is connected a reach rod 72 connected to a bell crank 7 3 one arm of which is provided with a hook 74 adapted to engage a pin 7 5 on a lever 76 which is connected to the rod 81 of valve 18, the arrangement being such that valve 18 will be alternately opened and closed by the rotation of crank disc 71, the relative time of open and closed positions being determined by the knock off block 80. It will, of course, be understood that disc 71 might be independently rotated if desired.

The relative time of open and closed operations of valve 18 may also be modified by the adjustment of the cam 80 movable into and out of the path of movement of the finger 81 of hook 74. Block 80 may be automatically positioned by means of a reach rod 82 actuated by the diaphragm of a diaphragm chamber 83 which chamber is connected by pipe 84: with the air delivery pipe 16. Cam 80 may be manually adjusted by means of an arm 87 and segment 88, if desired. 7

A dash pot 90 dampens the closing of valve 18.

I claim as my invention:

1. The combination of a fluid-pressure producer for a delivery system supplied thereby, a valved by-pass for the discharge of said producer, means synchronized with said producer for opening and closing said valve, and pressure-controlled means under the influence of pressure in the delivery system for determining the period of valve opening.

2. The combination of a fluid-pressure producer for a delivery system supplied thereby, a valved by-pass for the discharge side of said producer, pressure-controlled means under the influence of pressure in the delivery system, and means synchronized with the producer, both said means connected to and acting upon the valve to determine the extent and duration of its opening.

3. The combination of a fluid-pressure producer for a delivery system supplied thereby, a valved by-pass for the discharge side of said producer, a cam synchronized with the producer, an element actuated by said cam, means controlled by pressure in the dehvery system for shifting said element relative to the cam, and connections between the cam-actuated element and valve.

4. The combination of a fluid-pressure producer for a delivery system supplied, thereby a valved b -aass for the dischar e side of said producer, a cam synchronized with the producer, and means controlled by pressure in the delivery system for varying the effect of said cam on the valve.

producer for a delivery system supplied thereby, a valved by-pass for the discharge side of said producer and mechanically actuated means for regularly recurrently open- .95 5. The combination of a fluid-pressure ing and closing said valved by-pass and pressure controlled means under the influence of pressure in the delivery system for modifying the amplitude of the recurrent opening periods.

6. producer for a delivery system supplied thereby, two independent discharge outlets for said producer, one to be connected to the delivery system and the other to form a bypass away from such system, a valve in said by-pass for controlling outflow from the producer through said bypass, and mechanically-actuated means for recurrently manipulating said valve to vary outflow through the by-pass.

In witness whereof, I, WILLIAM TOWNSEND, have hereunto set my hand at Chicago, 111., this 21st day of October, A. D. one thousand nine hundred and twenty-seven.

lVILLIAM TOVJNSEND. 

